Ofloxacin

Description

DESCRIPTION Ofloxacin tablets are a synthetic broad-spectrum antimicrobial agent for oral administration. Chemically, ofloxacin, USP, a fluorinated carboxyquinolone, is the racemate, (±)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7 H -pyrido[1,2,3- de ]-1,4-benzoxazine-6-carboxylic acid. The chemical structure is: C 18 H 20 FN 3 O 4 M.W. 361.4 Ofloxacin, USP is an off-white to pale yellow crystalline powder. The molecule exists as a zwitterion at the pH conditions in the small intestine. The relative solubility characteristics of ofloxacin USP at room temperature, as defined by USP nomenclature, indicate that ofloxacin, USP is considered to be soluble in aqueous solutions with pH between 2 and 5. It is sparingly to slightly soluble in aqueous solutions with pH 7 (solubility falls to 4 mg/mL) and freely soluble in aqueous solutions with pH above 9. Ofloxacin USP has the potential to form stable coordination compounds with many metal ions. This in vitro chelation potential has the following formation order: Fe +3 > Al +3 > Cu +2 > Ni +2 > Pb +2 > Zn +2 > Mg +2 > Ca +2 > Ba +2 Ofloxacin tablets, USP contain the following inactive ingredients: lactose monohydrate, pregelatinized maize starch, hydroxy propyl methyl cellulose, talc, magnesium stearate, polyethylene glycol, sodium starch glycolate, and titanium dioxide. Additionally, the 200 mg and 400 mg tablets contain iron oxide yellow. The imprinting ink for 200 mg, 300 mg and 400 mg strength contains FD&C blue #1, isopropyl alcohol, Nbutyl alcohol, propylene glycol, shellac and titanium dioxide. ofloxacin-fig1-structure1

What Is Ofloxacin Used For?

INDICATIONS AND USAGE To reduce the development of drug-resistant bacteria and maintain the effectiveness of ofloxacin tablets, USP and other antibacterial drugs, ofloxacin tablets, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. Ofloxacin tablets, USP are indicated for the treatment of adults with mild to moderate infections (unless otherwise indicated) caused by susceptible strains of the designated microorganisms in the infections listed below. Please see DOSAGE AND ADMINISTRATION for specific recommendations. Acute Bacterial Exacerbations of Chronic Bronchitis (ABECB) due to Haemophilus influenzae or Streptococcus pneumonia . Because fluoroquinolones, including ofloxacin, have been associated with serious adverse reactions (see Warnings ), - and for some patients ABECB is self-limiting, reserve ofloxacin for treatment of ABECB in patients who have no alternative treatment options . Community-Acquired Pneumonia due to Haemophilus influenzae or Streptococcus pneumonia . Uncomplicated Skin and Skin Structure Infections due to methicillin-susceptible Staphylococcus aureus, Streptococcus pyogenes, or Proteus mirabilis. Acute, Uncomplicated Urethral and Cervical Gonorrhea due to Neisseria gonorrhoeae (see WARNINGS ). Nongonococcal Urethritis and Cervicitis due to Chlamydia trachomatis (see WARNINGS ). Mixed Infections of the Urethra and Cervix due to Chlamydia trachomatis and Neisseria gonorrhoeae (see WARNINGS ). Acute Pelvic Inflammatory Disease (including severe infection) due to Chlamydia trachomatis and/or Neisseria gonorrhoeae (see WARNINGS ). NOTE: If anaerobic microorganisms are suspected of contributing to the infection, appropriate therapy for anaerobic pathogens should be administered. Uncomplicated Cystitis due to Citrobacter diversus, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, or Pseudomonas aeruginosa. Because fluoroquinolones, including ofloxacin, have been associated with serious adverse reactions (see WARNINGS ), and for some patients uncomplicated cystitis is self-limiting, reserve ofloxacin for treatment of uncomplicated cystitis in patients who have no alternative treatment options. Complicated Urinary Tract Infections due to Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Citrobacter diversus,* or Pseudomonas aeruginosa.* Prostatitis due to Escherichia coli. * = Although treatment of infections due to this organism in this organ system demonstrated a clinically significant outcome, efficacy was studied in fewer than 10 patients. Appropriate culture and susceptibility tests should be performed before treatment in order to isolate and...

Dosage and Administration

DOSAGE AND ADMINISTRATION The usual dose of ofloxacin tablets is 200 mg to 400 mg orally every 12 h as described in the following dosing chart. These recommendations apply to patients with normal renal function (i.e., creatinine clearance > 50 mL/min). For patients with altered renal function (i.e., creatinine clearance < 50 mL/min), see the Patients With Impaired Renal Function subsection. Infection† Unit Dose Frequency Duration Daily Dose Acute Bacterial Exacerbation of Chronic Bronchitis 400 mg q12h 10 days 800 mg Comm. Acquired Pneumonia 400 mg q12h 10 days 800 mg Uncomplicated Skin and Skin Structure Infections 400 mg q12h 10 days 800 mg Acute, Uncomplicated Urethral and Cervical Gonorrhea 400 mg Single Dose 1 day 400 mg Nongonococcal Cervicitis/Urethritis due to C. trachomatis 300 mg q12h 7 days 600 mg Mixed Infection of the Urethra and Cervix due to C. trachomatis and N. gonorrhoeae 300 mg q12h 7 days 600 mg Acute Pelvic Inflammatory Disease 400 mg q12h 10 to 14 days 800 mg Uncomplicated Cystitis due to E. coli or K. pneumoniae 200 mg q12h 3 days 400 mg Uncomplicated Cystitis due to Other Approved Pathogens 200 mg q12h 7 days 400 mg Complicated UTI’s 200 mg q12h 10 days 400 mg Prostatitis due to E. coli 300 mg q12h 6 weeks 600 mg † DUE TO THE DESIGNATED PATHOGENS (see INDICATIONS AND USAGE ). Antacids containing calcium, magnesium, or aluminum; sucralfate; divalent or trivalent cations such as iron; or multivitamins containing zinc; or didanosine, chewable/buffered tablets or the pediatric powder for oral solution should not be taken within the two-hour period before or within the two-hour period after taking ofloxacin (see PRECAUTIONS ). Patients With Impaired Renal Function Dosage should be adjusted for patients with a creatinine clearance < 50 mL/min. After a normal initial dose, dosage should be adjusted as follows: Creatinine Clearance Maintenance Dose Frequency 20 to 50 mL/min the usual recommended unit dose q24h < 20 mL/min ½ the usual recommended unit dose q24h When only the serum creatinine is known, the following formula may be used to estimate creatinine clearance. Women: 0.85 x the value calculated for men. The serum creatinine should represent a steady-state of renal function. Patients With Cirrhosis: The excretion of ofloxacin may be reduced in patients with severe liver function disorders (e.g., cirrhosis with or without ascites). A maximum dose of 400 mg of ofloxacin per day should therefore not be exceeded. ofloxacin-fig3-formula

Side Effects (Adverse Reactions)

ADVERSE REACTIONS The following is a compilation of the data for ofloxacin based on clinical experience with both the oral and intravenous formulations. The incidence of drug-related adverse reactions in patients during Phase 2 and 3 clinical trials was 11%. Among patients receiving multiple-dose therapy, 4% discontinued ofloxacin due to adverse experiences. In clinical trials, the following events were considered likely to be drug-related in patients receiving multiple doses of ofloxacin: nausea 3%, insomnia 3%, headache 1%, dizziness 1%, diarrhea 1%, vomiting 1%, rash 1%, pruritus 1%, external genital pruritus in women 1%, vaginitis 1%, dysgeusia 1%. In clinical trials, the most frequently reported adverse events, regardless of relationship to drug, were: nausea 10%, headache 9%, insomnia 7%, external genital pruritus in women 6%, dizziness 5%, vaginitis 5%, diarrhea 4%, vomiting 4%. In clinical trials, the following events, regardless of relationship to drug, occurred in 1 to 3% of patients: abdominal pain and cramps, chest pain, decreased appetite, dry mouth, dysgeusia, fatigue, flatulence, gastrointestinal distress, nervousness, pharyngitis, pruritus, fever, rash, sleep disorders, somnolence, trunk pain, vaginal discharge, visual disturbances, and constipation. Additional events, occurring in clinical trials at a rate of less than 1%, regardless of relationship to drug, were: Body as a Whole: asthenia, chills, malaise, extremity pain, pain, epistaxis Cardiovascular System: cardiac arrest, edema, hypertension, hypotension, palpitations, vasodilation Gastrointestinal System: dyspepsia Genital/Reproductive System: burning, irritation, pain and rash of the female genitalia; dysmenorrhea; menorrhagia; metrorrhagia Musculoskeletal System: arthralgia, myalgia Nervous System: seizures, anxiety, cognitive change, depression, dream abnormality, euphoria, hallucinations, paresthesia, syncope, vertigo, tremor, confusion Nutritional/Metabolic: thirst, weight loss Respiratory System: respiratory arrest, cough, rhinorrhea Skin/Hypersensitivity: angioedema, diaphoresis, urticaria, vasculitis Special Senses: decreased hearing acuity, tinnitus, photophobia Urinary System: dysuria, urinary frequency, urinary retention The following laboratory abnormalities appeared in ≥ 1% of patients receiving multiple doses of ofloxacin. It is not known whether these abnormalities were caused by the drug or the underlying conditions being treated. Hematopoietic: anemia, leukopenia, leukocytosis, neutropenia, neutrophilia, increased band forms, lymphocytopenia, eosinophilia, lymphocytosis, thrombocytopenia, thrombocytosis, elevated ESR Hepatic: elevated: alkaline phosphatase, AST (SGOT), ALT (SGPT) Serum Chemistry: hyperglycemia, hypoglycemia, elevated creatinine, elevated BUN Urinary: glucosuria, proteinuria, alkalinuria, hyposthenuria, hematuria, pyuria Postmarketing Adverse Events Additional adverse events, regardless of relationship to drug, reported from worldwide marketing experience with quinolones, including ofloxacin: Clinical Cardiovascular System: cerebral thrombosis, pulmonary edema, tachycardia, hypotension/shock, syncope, torsade de pointes. Endocrine/Metabolic: hyper- or hypoglycemia, especially in diabetic patients on insulin or oral hypoglycemic agents (see PRECAUTIONS , General and Drug Interactions ). Gastrointestinal System: hepatic dysfunction including: hepatic necrosis, jaundice (cholestatic or hepatocellular), hepatitis; intestinal perforation; hepatic failure (including fatal cases); pseudomembranous colitis (the onset of pseudomembranous colitis symptoms may occur during or after antimicrobial treatment), GI hemorrhage; hiccough, painful oral mucosa, pyrosis (see WARNINGS ). Genital/Reproductive System: vaginal candidiasis Hematopoietic: anemia, including hemolytic and aplastic; hemorrhage, pancytopenia, agranulocytosis, leukopenia, reversible bone marrow depression, thrombocytopenia, thrombotic thrombocytopenic purpura,...

Drug Interactions

Drug Interactions Antacids, Sucralfate, Metal Cations, Multivitamins Quinolones form chelates with alkaline earth and transition metal cations. Administration of quinolones with antacids containing calcium, magnesium, or aluminum, with sucralfate, with divalent or trivalent cations such as iron, or with multivitamins containing zinc or with didanosine, chewable/buffered tablets or the pediatric powder for oral solution may substantially interfere with the absorption of quinolones resulting in systemic levels considerably lower than desired. These agents should not be taken within the two-hour period before or within the two-hour period after ofloxacin administration (see DOSAGE AND ADMINISTRATION ). Caffeine Interactions between ofloxacin and caffeine have not been detected. Cimetidine Cimetidine has demonstrated interference with the elimination of some quinolones. This interference has resulted in significant increases in half-life and AUC of some quinolones. The potential for interaction between ofloxacin and cimetidine has not been studied. Cyclosporine Elevated serum levels of cyclosporine have been reported with concomitant use of cyclosporine with some other quinolones. The potential for interaction between ofloxacin and cyclosporine has not been studied. Drugs Metabolized by Cytochrome P450 Enzymes Most quinolone antimicrobial drugs inhibit cytochrome P450 enzyme activity. This may result in a prolonged half-life for some drugs that are also metabolized by this system (e.g., cyclosporine, theophylline/methylxanthines, warfarin) when coadministered with quinolones. The extent of this inhibition varies among different quinolones (see other Drug Interactions ). Non Steroidal Anti-Inflammatory Drugs The concomitant administration of a non-steroidal anti-inflammatory drug with a quinolone, including ofloxacin, may increase the risk of CNS stimulation and convulsive seizures (see WARNINGS and PRECAUTIONS , General ). Probenecid The concomitant use of probenecid with certain other quinolones has been reported to affect renal tubular secretion. The effect of probenecid on the elimination of ofloxacin has not been studied. Theophylline Steady-state theophylline levels may increase when ofloxacin and theophylline are administered concurrently. As with other quinolones, concomitant administration of ofloxacin may prolong the half-life of theophylline, elevate serum theophylline levels, and increase the risk of theophylline-related adverse reactions. Theophylline levels should be closely monitored and theophylline dosage adjustments made, if appropriate, when ofloxacin is coadministered. Adverse reactions (including seizures) may occur with or without an elevation in the serum theophylline level (see WARNINGS and PRECAUTIONS , General ). Warfarin Some quinolones have been reported to enhance the effects of the oral anticoagulant warfarin or its derivatives. Therefore, if a quinolone antimicrobial is administered concomitantly with warfarin or its...

Contraindications

CONTRAINDICATIONS Ofloxacin tablets are contraindicated in persons with a history of hypersensitivity associated with the use of ofloxacin or any member of the quinolone group of antimicrobial agents.

Pregnancy and Breastfeeding

Pregnancy Teratogenic Effects Pregnancy Category C Ofloxacin has not been shown to have any teratogenic effects at oral doses as high as 810 mg/kg/day (11 times the recommended maximum human dose based on mg/m 2 or 50 times based on mg/kg) and 160 mg/kg/day (4 times the recommended maximum human dose based on mg/m 2 or 10 times based on mg/kg) when administered to pregnant rats and rabbits, respectively. Additional studies in rats with oral doses up to 360 mg/kg/day (5 times the recommended maximum human dose based on mg/m 2 or 23 times based on mg/kg) demonstrated no adverse effect on late fetal development, labor, delivery, lactation, neonatal viability, or growth of the newborn. Doses equivalent to 50 and 10 times the recommended maximum human dose of ofloxacin (based on mg/kg) were fetotoxic (i.e., decreased fetal body weight and increased fetal mortality) in rats and rabbits, respectively. Minor skeletal variations were reported in rats receiving doses of 810 mg/kg/day, which is more than 10 times higher than the recommended maximum human dose based on mg/m 2 . There are, however, no adequate and well-controlled studies in pregnant women. Ofloxacin should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus (see WARNINGS ).

Nursing Mothers In lactating females, a single oral 200 mg dose of ofloxacin resulted in concentrations of ofloxacin in milk that were similar to those found in plasma. Because of the potential for serious adverse reactions from ofloxacin in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother (see WARNINGS and ADVERSE REACTIONS ).

Overdosage

OVERDOSAGE Information on overdosage with ofloxacin is limited. One incident of accidental overdosage has been reported. In this case, an adult female received 3 grams of ofloxacin intravenously over 45 minutes. A blood sample obtained 15 minutes after the completion of the infusion revealed an ofloxacin level of 39.3 mcg/mL. In 7 h, the level had fallen to 16.2 mcg/mL, and by 24 h to 2.7 mcg/mL. During the infusion, the patient developed drowsiness, nausea, dizziness, hot and cold flushes, subjective facial swelling and numbness, slurring of speech, and mild to moderate disorientation. All complaints except the dizziness subsided within 1 h after discontinuation of the infusion. The dizziness, most bothersome while standing, resolved in approximately 9 h. Laboratory testing reportedly revealed no clinically significant changes in routine parameters in this patient. In the event of an acute overdose, the stomach should be emptied. The patient should be observed and appropriate hydration maintained. Ofloxacin is not efficiently removed by hemodialysis or peritoneal dialysis.

How Supplied

HOW SUPPLIED Ofloxacin tablets USP, 200 mg are available as light yellow to yellow, oval, biconvex, film coated tablets, imprinted with “C213” in blue ink on one side and plain on the other side. They are available in bottles of 50, 100 and 500 tablets.. Bottles of 50 (NDC 71209-097-02) Bottles of 100 (NDC 71209-097-05) Bottles of 500 (NDC 71209-097-10) Ofloxacin tablets USP, 300 mg are available as white to off white, oval, biconvex, film coated tablets, imprinted with “C212” in blue ink on one side and plain on the other side.. They are available in bottles of 50, 100 and 500 tablets. Bottles of 50 (NDC 71209-098-02) Bottles of 100 (NDC 71209-098-05) Bottles of 500 (NDC 71209-098-10) Ofloxacin tablets USP, 400 mg are available as yellow to dark yellow, oval, biconvex, film coated tablets, imprinted with ‘C211’ in blue ink on one side and plain on other side. They are available in bottles of 50, 100 and 500 tablets. Bottles of 50 (NDC 71209-099-02) Bottles of 100 (NDC 71209-099-05) Bottles of 500 (NDC 71209-099-10) Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature]. Dispense in a tight, light-resistant container as defined in the USP, with a child-resistant closure (as required) KEEP THIS AND ALL MEDICATIONS OUT OF THE REACH OF CHILDREN.